1. Field of the Invention
The present invention relates to a toner container for use with a copier, printer, facsimile apparatus, multifunction machine or similar image forming apparatus, a toner replenishing device using the same, a developing device, a process cartridge and an image forming apparatus.
2. Description of the Background Art
It is a common practice with a copier or similar image forming apparatus to use a toner container implemented as a bottle and removably mounted to the apparatus body. Toner stored in the toner container is consumed little by little by repeated development, which forms part or an image forming process. When the toner container substantially runs out of toner, it is suitably replaced with a new toner bottle by the user.
Japanese Patent Laid-Open Publication No. 6-59576, for example, discloses a bottle-like toner container generally made up of a major portion or bottle body and a cylindrical portion or cap contiguous with the front end of the major portion. A toner outlet is formed in part of the cylindrical portion so as to feed toner stored in the toner container.
More specifically, a shutter or shutter member usually closes the toner outlet of the cylindrical portion and is movable along the periphery of cylindrical portion. When the toner container is mounted to a toner replenishing device or toner hopper included in the body of an image forming apparatus, the cylindrical portion of the toner container is brought into engagement with a mount portion included in the toner replenishing device. Subsequently, when a knob included in the mount portion is turned in the circumferential direction, the shutter is moved to open the toner outlet. As a result, toner is replenished from the toner container to the toner replenishing device via the toner outlet.
A seal member is adhered between the toner outlet and shutter of the cylindrical portion in order to prevent the toner from flying about out of the toner container before the toner container is mounted to the apparatus body.
With the prior art toner container described above, it is extremely difficult to enhance both of sealability of the toner outlet and easy operation for opening the toner outlet.
More specifically, it is a common practice with a toner container to adhere a seal member formed of, e.g., foam polyurethane or rubber between the toner outlet and the shutter of the cylindrical portion in order to surely seal the toner outlet. The seal member seals the portion around the toner outlet, which is open on the circumferential wall of the cylindrical portion, in cooperation with the shutter when the shutter is closed. Therefore, the toner outlet can be more surely sealed if the compression ratio of the seal member, for example, is made greater. Also, sealability can be increased if use is made of a material having high adhesion.
On the other hand, if the seal pressure or adhesion of the seal member is high, then it is difficult to open or close the shutter when the toner container is mounted to or dismounted from the apparatus body. More specifically, when the toner outlet is opened or closed, the shutter slides on the circumferential surface of the cylindrical portion with the seal surface of the seal member sliding on the circumferential surface. It follows that the higher the seal pressure or the adhesion of the seal surface of the seal member, the greater the frictional force to act when the shutter is slid, i.e., the lower the operability. Moreover, if the seal pressure or adhesion of the seal member is excessively high, then the frictional force acting against the slide of the shutter overcomes, e.g., the shearing strength of the seal member and causes the seal member to come off.